Documents disponibles écrits par cet auteur

Evaluation of the effect of the concentration of CO2 on the overall reactivity of drop tube furnace derived indian sub - bituminous coal chars during CO2/O2 combustion / V. Saravanan in Industrial & engineering chemistry research, Vol. 50 N° 23 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12865–12871 Titre : Evaluation of the effect of the concentration of CO2 on the overall reactivity of drop tube furnace derived indian sub - bituminous coal chars during CO2/O2 combustion Type de document : texte imprimé Auteurs : V. Saravanan, Auteur ; R. Shivakumar, Auteur ; Jayanti, S., Auteur Année de publication : 2012 Article en page(s) : pp. 12865–12871 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nonisothermal  Thermogravimetric  Derived Résumé : A nonisothermal thermogravimetric analysis technique was used to evaluate the effect of CO2 concentration on the overall reactivity of Indian coal chars during CO2/O2 combustion. The study was carried out for the drop tube furnace derived chars of three Indian sub-bituminous coals from different sources. The selected coal char samples were combusted in different CO2/O2 molar volume combinations, namely, 80:20, 60:40, 40:60, 20:80, and 0:100 (pure O2) so that the effect of the concentration of CO2 on the overall reaction rate could be quantified. The Arrhenius constants (E and A) were determined using the random pore model. The concept of weighted mean activation energy was used to account for the multi-Arrhenius linearities. Empirical equations were proposed to evaluate the Arrhenius constants in terms of the mole fraction of CO2 for the overall reaction rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1019358 [article] Evaluation of the effect of the concentration of CO2 on the overall reactivity of drop tube furnace derived indian sub - bituminous coal chars during CO2/O2 combustion [texte imprimé] / V. Saravanan, Auteur ; R. Shivakumar, Auteur ; Jayanti, S., Auteur . - 2012 . - pp. 12865–12871. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12865–12871 Mots-clés : Nonisothermal  Thermogravimetric  Derived Résumé : A nonisothermal thermogravimetric analysis technique was used to evaluate the effect of CO2 concentration on the overall reactivity of Indian coal chars during CO2/O2 combustion. The study was carried out for the drop tube furnace derived chars of three Indian sub-bituminous coals from different sources. The selected coal char samples were combusted in different CO2/O2 molar volume combinations, namely, 80:20, 60:40, 40:60, 20:80, and 0:100 (pure O2) so that the effect of the concentration of CO2 on the overall reaction rate could be quantified. The Arrhenius constants (E and A) were determined using the random pore model. The concept of weighted mean activation energy was used to account for the multi-Arrhenius linearities. Empirical equations were proposed to evaluate the Arrhenius constants in terms of the mole fraction of CO2 for the overall reaction rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1019358

Investigation of high - frequency, high - intensity ultrasonics for size reduction and washing of coal in aqueous medium / B. Ambedkar in Industrial & engineering chemistry research, Vol. 50 N° 23 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13210-13219 Titre : Investigation of high - frequency, high - intensity ultrasonics for size reduction and washing of coal in aqueous medium Type de document : texte imprimé Auteurs : B. Ambedkar, Auteur ; R. Nagarajan, Auteur ; Jayanti, S., Auteur Année de publication : 2012 Article en page(s) : pp. 13210-13219 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous  medium  Coal  Washing Résumé : While ultrasonic coal-wash is not entirely new in many countries, it has not yet been practiced in India, though it would appear that the relatively high-ash content of Indian coals would render them particularly suitable for such a washing procedure. In this study, state-of-the-art ultrasonic equipment, spanning the frequency range from highly cavitational (< 100 kHz), to mostly acoustic-streaming dominated (> 100 kHz), were used. The coal to be studied was received from Giral mine, Rajasthan, India. Four stages for ultrasound assisted coal particle breakage have been proposed and characterized with SEM images of sonicated coal. Sono-treatment, followed by the decanting process, has been found to remove detached ash effectively. Decanted coal samples were analyzed by SEM/EDX to determine the mechanism of ash removal by sonication. The present investigation also encompasses aqueous-based ultrasonic coal desulfurization. Ultrasound in aqueous medium produces OH, H2O2, HO2, O2, and ozone, which are strong oxidizing agents. The oxidation occurring in the presence of ultrasound is called αadvanced oxidation process", and this converts the sulfur present in the coal to water-soluble sulfates, thereby enhancing sulfur removal. Larger-scale trials with high-ash and sulfur coals are strongly recommended. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25267476 [article] Investigation of high - frequency, high - intensity ultrasonics for size reduction and washing of coal in aqueous medium [texte imprimé] / B. Ambedkar, Auteur ; R. Nagarajan, Auteur ; Jayanti, S., Auteur . - 2012 . - pp. 13210-13219. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13210-13219 Mots-clés : Aqueous  medium  Coal  Washing Résumé : While ultrasonic coal-wash is not entirely new in many countries, it has not yet been practiced in India, though it would appear that the relatively high-ash content of Indian coals would render them particularly suitable for such a washing procedure. In this study, state-of-the-art ultrasonic equipment, spanning the frequency range from highly cavitational (< 100 kHz), to mostly acoustic-streaming dominated (> 100 kHz), were used. The coal to be studied was received from Giral mine, Rajasthan, India. Four stages for ultrasound assisted coal particle breakage have been proposed and characterized with SEM images of sonicated coal. Sono-treatment, followed by the decanting process, has been found to remove detached ash effectively. Decanted coal samples were analyzed by SEM/EDX to determine the mechanism of ash removal by sonication. The present investigation also encompasses aqueous-based ultrasonic coal desulfurization. Ultrasound in aqueous medium produces OH, H2O2, HO2, O2, and ozone, which are strong oxidizing agents. The oxidation occurring in the presence of ultrasound is called αadvanced oxidation process", and this converts the sulfur present in the coal to water-soluble sulfates, thereby enhancing sulfur removal. Larger-scale trials with high-ash and sulfur coals are strongly recommended. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25267476

Investigation of postflooding conditions in countercurrent gas--liquid flow / Maharudrayya, S. in Aiche journal, Vol. 48 N°2 (Fevrier 2002) 

Public ISBD [article]  in Aiche journal > Vol. 48 N°2 (Fevrier 2002) . - 212-220 p. Titre : Investigation of postflooding conditions in countercurrent gas--liquid flow Type de document : texte imprimé Auteurs : Maharudrayya, S., Auteur ; Jayanti, S., Auteur Article en page(s) : 212-220 p. Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Inondation  Poteau  Ecoulement  Courant  Eau  Tube  de  diamètre  Phase  Gaz  Pression  Corrélation  Paramètres Index. décimale : 660 Résumé : Systematic experiments were conducted to study the postflooding situation in air-water countercurrent flow in a tube of 0.025 m internal diameter with smooth inlet and outlet conditions for the two phases. The downflow rate of water and the pressure gradient were measured over a range of flow rates for test-section lengths of 0.6, 1.2 and 2.0 m. Additional experiments were conducted with increasing and decreasing water flow rates at a constant air flow rate. The length of the test section or the way the flooding point was approached did not significantly affect the onset of flooding. The data show that, as the gas flow rate is increased, the pressure gradient can fall significantly in the postflooding situation due to depleting the downflow rate of liquid. Dimensionless correlations are proposed to calculate the downflow rate and the pressure gradient given for overall flow parameters. Des expériences systématiques ont été entreprises pour étudier la situation d'inondation de poteau dans l'écoulement de contre-courant de l'eau d'air dans un tube de diamètre interne de 0.025 m avec des conditions douces d'admission et de sortie pour les deux phases. Vers le bas le débit de l'eau et le gradient de pression ont été mesurés sur une gamme des débits unitaires pour des longueurs de section d'essai de 0.6, 1.2 et 2.0 expériences additionnelles de M. ont été entreprises avec l'augmentation de et des taux décroissants d'écoulement d'eau à un débit d'air constant. La longueur de la section d'essai ou de la manière que le point d'inondation a été approché n'a pas affecté de manière significative le début de l'inondation. Les données prouvent que, à mesure que le débit de gaz est augmenté, le gradient de pression peut tomber de manière significative dans la situation d'inondation de poteau due à épuiser vers le bas le débit du liquide. On propose des corrélations sans dimensions pour calculer vers le bas le débit et le gradient de pression donnés pour au-dessus de tous les paramètres d'écoulement. DEWEY : 660.627.3 ISSN : 0001-1541 RAMEAU : Ecoulement liquide, Mécanique de fluide En ligne : www.aiche.org [article] Investigation of postflooding conditions in countercurrent gas--liquid flow [texte imprimé] / Maharudrayya, S., Auteur ; Jayanti, S., Auteur . - 212-220 p. Génie Chimique Langues : Anglais (eng) in Aiche journal > Vol. 48 N°2 (Fevrier 2002) . - 212-220 p. Mots-clés : Inondation  Poteau  Ecoulement  Courant  Eau  Tube  de  diamètre  Phase  Gaz  Pression  Corrélation  Paramètres Index. décimale : 660 Résumé : Systematic experiments were conducted to study the postflooding situation in air-water countercurrent flow in a tube of 0.025 m internal diameter with smooth inlet and outlet conditions for the two phases. The downflow rate of water and the pressure gradient were measured over a range of flow rates for test-section lengths of 0.6, 1.2 and 2.0 m. Additional experiments were conducted with increasing and decreasing water flow rates at a constant air flow rate. The length of the test section or the way the flooding point was approached did not significantly affect the onset of flooding. The data show that, as the gas flow rate is increased, the pressure gradient can fall significantly in the postflooding situation due to depleting the downflow rate of liquid. Dimensionless correlations are proposed to calculate the downflow rate and the pressure gradient given for overall flow parameters. Des expériences systématiques ont été entreprises pour étudier la situation d'inondation de poteau dans l'écoulement de contre-courant de l'eau d'air dans un tube de diamètre interne de 0.025 m avec des conditions douces d'admission et de sortie pour les deux phases. Vers le bas le débit de l'eau et le gradient de pression ont été mesurés sur une gamme des débits unitaires pour des longueurs de section d'essai de 0.6, 1.2 et 2.0 expériences additionnelles de M. ont été entreprises avec l'augmentation de et des taux décroissants d'écoulement d'eau à un débit d'air constant. La longueur de la section d'essai ou de la manière que le point d'inondation a été approché n'a pas affecté de manière significative le début de l'inondation. Les données prouvent que, à mesure que le débit de gaz est augmenté, le gradient de pression peut tomber de manière significative dans la situation d'inondation de poteau due à épuiser vers le bas le débit du liquide. On propose des corrélations sans dimensions pour calculer vers le bas le débit et le gradient de pression donnés pour au-dessus de tous les paramètres d'écoulement. DEWEY : 660.627.3 ISSN : 0001-1541 RAMEAU : Ecoulement liquide, Mécanique de fluide En ligne : www.aiche.org